Grinding wheel



M y 7 1929- H. D. COLMAN 1,712,255

GRINDING WHEEL Original Filed March 16, 1923 l: I rhmLs of Grinder INVEN'TEIJR 7 Howard Ca lman 4 W M m.

ATTYIE- Patented May 7, 1929. I.

I UNITED STATES 1,712,255 PATENT OFFICE.

HOWARD D. COLMAN, OF ROCKFORD, ILLINOIS, ASSIGNOR TO BARBER-COLMAN GOM- PANY, OF ROCKFORD, ILLINOIS, A CORPORATION OF ILLINOIS.

eninnme WHEEL.

Original application filed March 16, 1923, Serial No. 625,469. Divided and. this application filed January 9, i925. Serial No. 1,336.

" In application Serial No. 625,469 filed March 16, 1923, I have disclosed a machine division of said application Serial No.

In the accompanying drawings, Figure 1 is a fragmental plan view of a grinding machine embodying the features of my inven-= tion.

the operation of grinding one side of each tooth of a blank. I Fig. 3 is a fragmental view representing the operation of grinding the other side of 2 thetooth of'a blank.

For-the sake of brevity, the gear wheels, the sprocket wheels or other articles to be ground will be hereinafter referred to as blanks.

The grinding wheel A constituting' the subject of this invention has on its periphcry a series ofequidistant annular ribs A. For the sake of accuracy in grindin and simplicity in dressing, the grinding w eel 1s 1 so constructed that only fiat surfaces are utilized for grinding the teeth of the blanks. To this end the grinding wheel is given a frusto-conical form, one side of each of the ribs A being erpendicular to the axis of the grinding w eel. The grinding surfaces are indicated by the letter a. In a single passage of a blank across the periphery of the grinding wheel, only one side. of each tooth is ground. In-order thatthe opposite W side of each tooth may be ground theblank 'is positionedso as to present such opposite side of the tooth to the abrasive wheel, whereby the grinding of both sides of each tooth is effected in two passages of the blank 4 across the grinding wheel. It will'be evident from Figs. 2 and 3 that during one passage of the blank the fiat surfaces 0: constituted one side of each tooth of an imaginary rack and that during the other passage W of the blank said surfaces constitute the opposite-sideof said rackteeth.

The blanks are indicated at lb. j Each blank is rigidly secured to an arbor 0 by means of which the blank is supported durwheel.

Fig. 2 is a fragmental view illustrating ing the grinding operation and during its travel in the machine, and through which rolhng movement is imparted to the blank while it is passing the grinding wheel. The gr nding wheel has the same number of grinding surfaces a as there are teeth on the blank, consequently it is possible to pass three blanks in close succession past the. I therefore support the blanks on cars 4, each adapted to support three arbors 0. Suitable means, such as master gearing,

may be provided to cause the blanks to roll across the periphery of the grinding wheel in the travel of the car.

It will be seen that while a blank 6 is being rolled past the periphery of the grind ing wheel on one side of the latter, one side of each tooth of'the blank will be ground, and that while the blank is rolling past the grinding wheel diametrically opposite the place where the first grinding operation occurs, the other side of each tooth will be ground.

, The grinding wheel is made of sufficiently [large diameter so that the necessary peripheral s eed is obtained at the small end of the w eel. The diameter of the grinding wheel may be so great with relation to the thickness of the'blank that there is no objectionable concaving. of the bottoms of the interdental spaces of the blank.

I claim as my invention:

.1. A frusto-conical gear grinding wheel having upon its periphery a plurality of equidistant annular plane grinding surfaces which are perpendicular to the axis of the wheel.

2. A gear-grinding wheel having on its eriphery a series of plane grinding suraces constituting in effect elements of a series ofimaginary rack teeth, said wheel being'of relatively large diameterand wide peripheral face as compared with the diameter'and thickness of the gear to be ground.

3. The combination of a plurality of rotary equidistant annular plane gear grinding surfaces, each perpendicular to its axis of rotation, the number of said surfaces be ing equal to the number of teeth on the blank to be ground.

In testimony whereof, I. have hereunto affixed my signature.

HOWARD D. ooLMAn. 

